


A Hero's a Hero, No Matter How Small...And a Bad Guy's a Bad Guy, No Matter How Tall

by leveragehunters (Monkeygreen)



Series: A Game of Cat and Mouse [3]
Category: Captain America (Movies)
Genre: Additional Warnings In Author's Note, Alternate Universe - Animals, Alternate Universe - Magical Realism, Alternate Universe - Modern with Magic, Alternate Universe - Modern: No Powers, Angst, Bucky Barnes is a Cat, Familiar Bucky Barnes, Familiar Steve Rogers, Fluff, Happy Ending, Illustrations, Look I just love mice okay?, M/M, Mice, Minor Violence, Pied Piper of Hamelin references, Rats, Rats & Mice, Steve Rogers is a Mouse, They're so brave and small, Witch Natasha Romanov, animal mind control, animal to human transformation, original rodent characters, pied piper elements
Language: English
Status: Completed
Published: 2019-11-22
Updated: 2019-11-22
Packaged: 2021-02-07 13:22:38
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 9,598
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/21458734
Author URL: https://archiveofourown.org/users/Monkeygreen/pseuds/leveragehunters
Summary: Steve popped out of the scraggly bushes, ears and whiskers twitching. "Do you hear…" His voice trailed off and then he was dashing away.Bucky was so shocked it took him a second to follow. It took him even longer to realise Steve wasn't alone. He was the tail end of a race, mice and rats chasing something Bucky couldn’t sense. He yowled Steve's name, but it was like yelling at a brick wall for all the reaction he got. All he could do was keep up and not lose him, because something was making Steve run and whatever was waiting at the end of this, Bucky intended to be there.
Relationships: James "Bucky" Barnes & Natasha Romanov, James "Bucky" Barnes/Steve Rogers
Series: A Game of Cat and Mouse [3]
Series URL: https://archiveofourown.org/series/1064534
Comments: 58
Kudos: 671





	A Hero's a Hero, No Matter How Small...And a Bad Guy's a Bad Guy, No Matter How Tall

**Author's Note:**

> Apologies to Dr Seuss, but I seem to be making a habit of long-ass titles for this series--not unlike my tradition of writing a self-indulgent fic for my birthday. I truly didn't think I'd make it this year, what with how long writing's been taking me lately, but I just couldn't break my tradition (even if I had to abuse time zones to do it), so for this year's self-indulgent birthday fic I bring you more Cat!Bucky and Mouse!Steve... INCLUDING GORGEOUS ART BY ALBY. <3 <3 THANK YOU SO MUCH ALBY YOU ARE AMAZING!! 
> 
> (You can see more of [alby_mangroves](https://archiveofourown.org/users/Alby_Mangroves)'s amazing art [here](https://artgroves.tumblr.com/).)
> 
> Note: While not one single animal dies in this fic, there is a reference to some rats who died before the story started.

_He advanced to the council-table:_  
_And, "Please your honours," said he, "I'm able,_  
_By means of a secret charm, to draw_  
_All creatures living beneath the sun,_  
_That creep or swim or fly or run,_  
_After me so as you never saw!_  
_And I chiefly use my charm_  
_On creatures that do people harm,_  
_The mole and toad and newt and viper;  
_ _And people call me the Pied Piper."_

-_The Pied Piper of Hamelin_, Robert Browning

* * *

Bucky's eyes were closed. He was breathing deep and even. His tail hung down from the shelf like a clock's pendulum, the occasional tick measuring off the minutes Natasha had spent talking with Sam.

Obviously he was asleep.

_Obviously_.

The tiny prick of Steve's claws as he scrambled up his tail tickled, but Bucky didn't twitch. Not even when Steve ambled up his back to the top of his head, perched between his ears, and leaned down to brace both front paws on his nose.

"You're being rude."

Obvious or not, he'd never fool Steve. He wouldn't have before the magic had decided to bind them together, and he sure as heck couldn't now.

Bucky cracked open one eye. Steve's whiskers were curling in amusement. "I'm being a cat."

"And the difference is…?"

He cracked open the other eye. "Style."

Steve laughed so hard he slipped right down Bucky's face and landed on the shelf in front of him. Disgruntled, Bucky opened his eyes properly and sat up. Steve had blown his cover and pretending to sleep when everyone knew he was pretending would just be embarrassing.

He swiped his tongue across Steve's back and Steve flatted his ears. "Bucky," he hissed. "We've got guests."

"_Natasha_ has guests. We have," he slanted a glare at the large black and red bird perched on the back of Sam's chair, "irritations."

Steve harrumphed and fixed him with a stern look.

_Mice. _They had _views_ about guests. It was ridiculous, but Bucky extended his front leg so Steve could scamper up to his shoulders then leapt off the shelf, sauntering over to where Sam and Natasha were deep in conversation, because he couldn't refuse Steve anything. If he ever learned how to he'd…

Well, it didn't matter what he'd hypothetically do, because he knew he never would. He didn't want to. He was Steve's, from the tip of his tail to his quick-beating heart, and the only reason it didn't rankle—and it should, he was a _cat_—was that Steve belonged to him just as hard.

Bucky settled next to Natasha's chair, rubbing his head against her fingers when she lowered her hand to scratch his head. He felt Steve lift up on his back legs, knew he was nibbling her nails, because mice were weird, and met the amused gaze of Redwing, Sam's familiar.

"Bucky," she said, and cracked her beak, a wickedly curved thing Bucky was sure she'd stolen from a bird of prey, since it didn't belong on a mouthy parrot. "Nice of you to join us."

Bucky lashed his tail and ignored her. Steve slid down his shoulder, planted himself under his chest, and cocked his head, gazing up at her. "Something you want to say?"

"Nothing. Nothing." She shifted on the chair-back and Sam reached up to scratch her chest, distracting her.

Bucky rolled his eyes. Redwing was a familiar bred and born who'd chosen Sam as a chick, not a found familiar like him. She was tolerable, as far as birds went, but of the two of them, he far preferred Sam.

Sam, who was saying, "It was weird, Nat, is what I'm getting at. Even by our standards. You've never heard of anything like it?"

She shook her head. "Piles of dead rats? No, that's a new one for me. But you were searching the sewers. Aren't dead rats expected down there?"

"Live ones, yeah, those we run into, more than we can count. One or two dead ones, sure. But not like this. Not in _piles_. Not with something…_off_ about them."

"Magic?"

Sam grimaced, and Bucky could almost smell his frustration as he threw up his hands. "I don't know. Maybe."

"Helpful."

"Gimme a break, Nat. It was a whole bunch of decomposing rats piled against a wire grate, and we were down there trying to find a bunch of dumb-ass lost spelunkers. I couldn't go casting anything obvious, all I could pick up passively was that there was something off, and you know I don't take Redwing underground."

Steve turned to meet Bucky's eyes and then they both looked up at Natasha. Bucky knew Steve couldn’t see her, not from so far away, but he could read the shape of her, the scent of her, as well as Bucky. He'd be able to feel the worry spark from her as she leaned forward, one hand smoothing through Bucky's fur.

"You think it's something we should take seriously."

"I do. And so does Redwing."

The parrot clacked her beak and spread her wings, the vibrant red framing Sam like a halo.

"That's good enough for me." She leaned back and frowned thoughtfully. "We'll get the word out, but at this point all we can do is keep watch and try and keep any civilians from getting hurt."

Sam's mouth curled at the corner. "I can't believe you picked that up from Clint."

"What, civilians?" He nodded and she grinned. "It's as good a description as any, and it's better than muggle."

"Hey, I _liked_ muggle."

"And I told you, once you figure out how to make a broomstick fly, we'll all start using muggle."

Sam laughed and stood up. "You're a hard woman, Nat," he said, before pulling her into a hug. When she stepped back, he crouched and offered his hand to Bucky. "Sorry about not saying hi when I came in, but I know better than to disturb sleeping cats."

Bucky sniffed his hand then rubbed the side of his face against his fingers. He didn't usually, not to witches, but Sam's next action was why Sam got special treatment…bird familiar notwithstanding. "And Steve, always a pleasure." He held out a finger and Steve put both paws on it, sniffing gently, before dropping back to the ground.

Sam gave them both one last smile, then straightened and Redwing flew to his shoulder. As Sam turned to go, walking with Natasha to the apartment door, Bucky called, "Redwing. Do you really think there's something to worry about?"

"Maybe not worry, but there's _something_." She ruffled her feathers. "You watch yourself, you and the mouse, and take care of your witch."

* * *

Natasha _was_ his witch and Bucky was her familiar; the magic may have made Steve_ his_ familiar, but that hadn't changed. Bucky didn't need some bird telling him to look after her. He'd always look after her. And right now, she needed him.

Bucky sat on the table in her workroom, Steve crouched next to him, and they watched as she wove wood and wire and feathers and stripped network cables together in intricate patterns. Okay, maybe she didn't need him right this minute. This bit, she did on her own. The next part, the part where she infused her creations with magic, that bit she'd need him for.

She was taking Sam's concerns seriously. Even if he had chosen a bird for a familiar, and an annoying one at that, Sam was almost Natasha's equal as a witch. (If pressed, and pressed hard, Bucky might admit he was, perhaps, not entirely capable of making an unbiased judgement on the _who's the best witch _front. _Might._) Added to that, Sam spent his time rescuing people too stupid, or too unlucky, to keep themselves out of danger. If his instincts sensed something wrong, they were worth listening to.

Natasha set the pile of tiny knots on the table in front of them. Steve bounded forward to sniff them delicately.

"Go ahead," she said, and he picked one up, his clever paws as good as human hands, bracing it on the table and turning it over as he sniffed at it, poking his claws in here and there, before letting it settle back on the pile.

With a gentle touch on his back, Natasha breathed deep. Bucky matched her and Steve moved back to rest against his side.

Before, the magic had sparked freely between the three of them, but it was different now. Different, because Steve was _his_ familiar. The magic filling the room was Natasha's magic. It was Natasha's magic flowing through him, Natasha's magic that sparked off his fur as he fought to keep it from burning the tiny, delicate soon-to-be watchers to a crisp. It had always been Natasha's magic and however much it knew Steve, however much it had once jumped from Bucky to Steve and back again before Bucky sent it on to Natasha, Steve was _Bucky's_ now. Steve had become Bucky's familiar and a witch's magic didn't use someone else's familiar, regardless of how willing or familiar he might be.

He could still feel Steve, could still see the beautiful golden glow of his true self, but however much he could lean on Steve's strength as he coiled and controlled Natasha's magic, it was something Steve could no longer be part of.

When it was over, the scent of pine and cloves filling the workroom while the tiny knots pulsed alert and watchful in Bucky's senses, he stretched and yawned. Natasha sat on the workroom's stool and swept her gaze over both of them.

Steve's whiskers quivered and he sat up on his back legs, returning her gaze with interest. Bucky let his eyes slip half closed, since he knew what was coming. This was far from the first time they'd worked magic since Steve had become his familiar and after every working she'd subtly—or not so subtly—hinted that they needed to start figuring out what Steve being his familiar meant.

Turned out this time he was wrong. When she spoke, she asked, "Can I get the two of you to help set these up around the neighbourhood? You can get places I'd never be able to reach."

"What do you say, Buck?" Steve said. "Up for a midnight stroll?"

Of course they'd help. This was _his_ neighbourhood. His alleys, his streets. If whatever wrongness had pinged Sam's instincts—and Redwing's, he grudgingly acknowledged—tried to come here, he wasn't going to let them get taken by surprise.

"I take it this is a yes?" Natasha tugged his tail, her half-smile showing just a hint of tooth, because it was puffed out to twice its normal size. Steve stretched up to rub his head against Bucky's cheek and _his_ tail rattled back and forth in a mouse battle cry. For a moment they were united in perfect understanding the way they'd once been joined in the flow of Natasha's magic.

He bumped his head against Natasha's arm and she ran her fingers down his spine, touched the spot between Steve's ears. "Thanks. I'm going to head out, set the ones I can, talk to a few people." She gathered most of the tiny watchers as she stood. "I'll be back in a few hours." Her lips quirked. "Have fun."

Not too long after that, they heard the front door close. Steve's whiskers curved. Bucky's twitched, and he leapt off the table.

He shook himself, fur fluffing out, then reached for the rune Natasha had inscribed on his back, her magic flowing out and through and then he was standing on two feet, stretching his arm above his head. Feeling the long length of his spine stretch and crack as his fingers reached for the ceiling.

Steve ran his paws over his whiskers, then he caught his tail and started grooming it.

"Steve."

He looked up, bright black eyes gleaming, and canted his ears back in question.

Bucky waved a hand at him expectantly. Steve cocked his head and Bucky rolled his eyes. With a silent laugh Steve dropped his tail and leapt off the table. Bucky _felt _the tug of Natasha's magic through his bond with Steve as it raced through the rune tattooed on Steve's back. It itched under his skin as it flowed under Steve's, like ruffled fur he couldn't reach, but then Steve hit the floor in a crouch, still laughing up at Bucky out of eyes that glowed brilliant blue instead of gleaming black, and he forgot everything else.

"House to ourselves," Steve said, humming softly as he straightened and stretched.

Bucky pulled him close, fingers spread wide in the small of his back. He pressed his face against Steve's neck, breathing in deep, rubbed his cheek against Steve's, then switched sides and did it again. "For a few hours." 

Steve grinned, grabbed him by the hand and dragged him down the hall.

Steve had been right. They were a cat and a mouse. Living forever in these bodies would be impossible, but a few hours to enjoy them…

He pounced on Steve, scooped him up over his shoulder, earning himself a, "Bucky!" and a sharp nip on the ribs for his trouble, but then he was falling back on their couch with Steve sprawled across him. He had a second to appreciate the view then Steve was kissing him, hot and hard, hands sliding over his skin, a low hum vibrating out of his throat while Bucky wrapped his arm around Steve and dragged him closer.

* * *

"I swear, Steve, if anyone sees me, I'm going to have to get my fur bleached." Bucky slunk down the alley, belly low, on high alert. Not for danger, although he was watching for that too, but in case anyone saw him. There were some humiliations no amount of feline swagger could recover from. "I'm going to have to leave the city. I'm going to have to shave my fur and join the show circuit as one of those hairless cats." He shuddered.

"You know they're not actually hairless, right?" Steve said from his perch on Bucky's back.

Bucky glared over his shoulder, because there'd been a distinct lack of sympathy in Steve's voice.

"They've got a kind of downy fur, almost like a baby bird."

"How do you know that?"

"They had them at the pet store."

He paused with one paw in the air, glanced back at Steve again, but he didn't seem bothered by having mentioned the pet store. The place where someone had wanted to feed him to a snake. The place that made Bucky's guts writhe with fury just to think about.

Steve climbed over the canvas strap that was the source of Bucky's potential humiliation and tugged on the edge of his ear. "Are you thinking if you hold still like that no one will see you? Cause I gotta say, Buck, that's an awful prey-like move for a fierce predator like you. You thinking of making me a prophet and taking up dancing with pigeons after all?"

Bucky flattened his ears. "You're enjoying this, aren't you?"

"Maybe I'm just trying to distract you. Ever think of that?"

Bucky sat down and started grooming his empty shoulder. Steve had to clutch at his fur to keep from getting dislodged, but he resettled between his shoulder blades.

"My witch sends me out with a _pack_, like I'm some kind of _dog_," Bucky's tail lashed the ground, "and my mouse, who, I might add, is also my _familiar_, can't even manage a scrap of sympathy." He heaved a deeply put-upon sigh.

"_Your_ mouse, huh."

Bucky let his eyes slip half-way shut and didn't reply. He wasn't going to bother, not to something so obvious.

"I guess I could manage a little bit of sympathy." Steve slid off his back and scampered around to gaze up at him. "Poor kitty." Bucky hissed, but Steve just curled his tail around his paws and reached up to tug his whiskers. "Come on, let's get the rest of these set up."

Bucky heaved another sigh, this one even more put upon, took another careful look around, and then they were off. Truthfully, the canvas pack Natasha had sourced fit him perfectly, strapped around his belly and chest and over his shoulders so it didn't interfere with his movement. For the next few hours, he and Steve scrambled, clambered, shoved, dug, and slunk (so much slinking; Bucky would not be seen in this get-up for all the salmon in the _world_) their way into human-impossible places to leave Natasha's tiny watchers.

When they were done, they made their way to the top of the building and between Bucky's teeth and Steve's clever paws, they managed to undo the pack. Barely.

"That would have been easier if you'd used magic," Steve said, curling into the void of Bucky's missing leg.

Bucky looked out over the city, the moon half full above them, then rasped his tongue over Steve's head. "I know."

"Then I don't know why we had to do it the hard way." Steve groomed his whiskers, and Bucky wasn't sure if it was thoughtfully or irritably. Maybe both. "You turned me into a human; magicking off a pack has to be easier than that."

"It's different now."

"Because of me? Because I'm your familiar?" Steve's paws fell and he curled his tail around himself, fixing Bucky with a beady-eyed glare. "If you don't want me as your familiar, just say so."

"Don't be stupid," Bucky told him since he knew Steve wasn't serious. "I want you as my everything."

"Then _you_ stop being stupid and tell me what the problem is."

He shuffled his back paws, like he was searching for firmer ground to leap from—but there was no firmer ground here. Why, why was this so hard? He was a cat. This should be simple. Everything was supposed to be simple. That was the point of being a cat.

"Bucky."

_Cat, you're a cat. Doesn't matter if the ground crumbles under your feet, you still pounce. _"It wasn't my magic. It's never been my magic. Familiars don't have magic. Only _witches_ have magic. It's always been Natasha's. Hers to use, hers to call. I guide it for her, help her control it and shape it. And yeah, I call it, sometimes, because she's always been generous enough to teach me, to let me use it for myself, but it's never been _mine_."

"Only witches have magic," Steve said slowly, catching his tail between his paws and grooming it while he thought. Then his whiskers quivered. "Bucky."

He kept his gaze firmly on the half-ripe moon.

"And only witches have familiars." Steve dropped his tail. "_Bucky_."

"_What_?" He didn't mean to snap, immediately said, "Sorry, Steve," and as Steve gazed up at him, continued, "But I'm a _cat_. I'm a familiar and a cat and I know you're my familiar, I _know_ you are. You're tied to my heart, I can feel it and I wouldn't undo it for anything, but it can't mean…that."

After a moment's pause, Steve said, "Okay," and leaned against his front leg. "Whatever it means, just like you said: we've got a long time to figure it out."

Warmth spread out from where Steve was leaning on him, filling him up, turning him into that gooey kitten Steve had accused him of being that first day. "Together," he corrected, gently nudging Steve with his nose.

"What?"

"I said we had a long time _together _to figure it out."

Steve curled a paw in his fur. "_Together_ goes without saying."

* * *

The watchers Natasha built were tiny but strong. Even so, they detected nothing out of the ordinary. Sam's pursuit of the idiotic and unlucky in need of rescuing took him and Redwing all over the city and into the wilds beyond, but the only unusual thing he encountered was a cow wearing pants—caused by drunken humans and nothing to do with magic. The witches of the city Natasha counted among her friends, and the ones she simply counted on, reported…nothing.

As the days passed and turned into weeks, they dutifully kept checking, but it wasn't from any expectation they'd have sensed anything worth being sensed. Even so, twice a week, on different nights at different times, Steve and Bucky prowled through the neighbourhood to check the watchers, half-hunting each other through the darkness.

Bucky was ever-alert to new cats that wouldn't have learned yet not to touch the small grey mouse that reeked of cat—but even on his own Steve was a force to be reckoned with, fast and sharp and aware of the world in a way Bucky figured no mouse had ever been.

Even so, even with everything they'd learned together, with everything Steve had become, he was, and always would be, a mouse.

The music that twisted and squirmed through the air as they patrolled that night was inaudible to almost everyone. Bucky couldn't hear it as he stalked Steve through optimistically placed municipal greenery, but it travelled down the streets, reaching, seeking…

It was sound without soul, magic without heart or will to guide it. If Bucky could have heard it, his fur would have stood on end at the wrongness. Magic needed will. It _needed_ heart. Magic meant giving as much as you took, meant understanding and responsibility and consequences. At least, _actual_ magic did. But there was other magic, spells that had been cast into objects, and anyone could use that magic...which was the problem. Once it left your hands, you could never know if the next person to pick up the hammer you'd made would use it to build a house or smash open a skull.

_Bucky_ didn't hear the magical, soulless music, but Steve did. He popped out of the scraggly bushes behind Bucky, ears twitching. "Do you hear…" His voice trailed off and then he was dashing away, faster than Bucky had ever seen, like an army of bloodthirsty cats was on his tail and he had to run for his life.

Bucky was so shocked it took him a second to follow. It took him even longer to realise Steve wasn't alone. He was the tail end of a race, mice and rats chasing something—or running from something?—he couldn’t see and couldn't sense. He yowled Steve's name, but he might as well have been yelling at a brick wall for all the reaction he got. Bucky dug in as they ran through the city, because they were small and twisty, and he was bigger and slower, and he didn't have as many legs as they did, and all he could do was _keep up_, all he could do was not lose him, because something was _making_ Steve run and whatever was waiting at the end of this, Bucky intended to be there.

They converged as they ran, becoming a small sea of brown bodies, Steve a cresting wave of grey fur, and then they flowed up and over the sidewalk and through a suddenly opened door. Bucky hurled himself after them. A booted foot tried to block him, but he dodged around it, diving for Steve, only to be caught by the scruff of the neck and hauled up. He twisted, lashed out with his claws, screaming his anger as they scraped harmlessly down long leather gloves. Claws were better, but a fist would do, and he reached for the power to turn human and deal with this man who was holding a wooden flute to his lips while Bucky dangled from his other hand—

And then the door slammed shut and took his connection to Natasha with it.

* * *

If Bucky had been in any mood for objectivity, he would have admitted that the matter-of-fact way the man dealt with a hissing, spitting, yowling Bucky while mice and rats swarmed around his feet and never let the flute pressed against his mouth waver was a little bit impressive.

But he was not feeling objective. Objective was so far away it might as well have been on the moon. He was angry—not _scared_, never scared, cats didn't get scared, even when they couldn't feel the connection to their witch and the rune on their back was nothing but dead, lifeless ink, not even when their mouse was acting like a…like a _mouse_—he was _furious_, he wanted to sink his claws into this asshole and rip him to shreds.

The grungy, dimly lit stairs led to a grungier basement, but this was brightly lit. It wasn't a kindness. The walls were cement, the floor was cement, both filthy with caked on grime. The collected stink of years almost made Bucky gag up a hairball. There was a row of large empty cages along the wall, maybe dog kennels, but Bucky didn't smell any sign of dog, with another row stacked on top. _Put me in one of those, I'll be out so fast and then we'll see. You don't have any gloves on your crotch. _He flexed his claws, ignored how much hanging by his scruff was starting to hurt_. _The middle of the room was a pen, fenced off with smooth metal panels, and the man walked inside, the rats and mice following, and he shut the gate. There was a cage hanging from the ceiling above them and he shoved Bucky inside.

Or he tried to. Bucky fought him, hissing and spitting, and managed to get in a good swipe across his neck. His claws went deep and blood flowed. Bucky wasn't messing around. This man had taken _Steve_.

He swore, flute falling from his lips as he clapped that hand against the wound, then he shook the cage hard enough Bucky slid down the metal and slammed the door shut.

"BUCKY!"

"Steve!" He shoved his nose against the front of the cage to peer out. Steve was standing in the middle of a mob of panicking rodents, all racing to get away from the human in their midst, scrabbling helplessly against the slippery metal panels.

"Bucky, what's going on. Where am I? What's—"

A big rat ran right over the top of him, sending him flying. Bucky yowled a warning, but Steve picked himself up and stood up on his back legs, stretching up towards Bucky.

"I don't know. You started to ask if I heard something then you started running."

He could see Steve thinking, see him trying to remember, then the man lifted the flute to his lips. Every mouse and every rat stopped. As one they turned to face him, then scampered calmly over to sit at his feet.

Every mouse, including Steve.

Bucky could still feel the connection that tied Steve to his heart, but that was all that was left of him.

Smiling in satisfaction, the man lifted a mouse by the tail, then turned a look on Bucky that made his blood run cold. He lowered the flute. Below him, the panic resumed. The mouse he was holding writhed and twisted, eyes wide with terror.

Steve called his name, but he didn't answer, he needed to focus on what the man was saying. "I can't use a cat, not yet. I know, I already tried and you're all too damn stubborn." He looked down at the mouse. "But these little guys are useless and once I've got the power I'm after, it's not going to matter how stubborn you are."

He stepped closer, blood trickling down his neck from Bucky's claws.

"I'll make you a deal." He wiggled the mouse and it swung helplessly. "All the mice you can eat, and when I'm done with all this." He waved the mouse at the cages against the wall. "You can be my main familiar. A cat's a lot more dignified than a bunch of rats." He smirked. "Traditional, even. Sound good?"

Bucky…didn't react. It was one of the hardest things he'd ever done. Was this man a witch? He didn't feel like a witch, but that didn't tell him anything. Sam pulsed with power like a small sun, regardless of what he was doing—Bucky could feel him coming from down the block—but unless Clint was actually casting a spell, he felt just like every other human.

But _something_ had blocked him from Natasha. Wards that strong could only come from magic that strong. He looked down at the pen full of panicking rodents, slowly filling up with dread.

"You know it does." He gave Bucky a sly grin, like they had an understanding, like they were allies, like Bucky would ever have anything to do with someone like this, then he dropped the mouse and put the flute back to his mouth.

Even though he heard nothing, Bucky knew he had to be playing it. The mice and rats instantly calmed, running over to sit at the man's feet, and the fierce and instant wave of fury surprised him. Not the fury itself, but that it wasn't just for Steve. It was for all of them. He didn't hunt mice any more, not since Steve, but he used to. He still hunted rats and they were as fierce as mice were canny. They deserved better than this. They deserved a _chance_.

One by one, the man shoved the mice into the cage with Bucky, moving fast and using his leather-gloved hand to block Bucky's escape. When he was done, Bucky had over a dozen small brown mice keeping him company along with an ancient, one-eyed rat the man had pronounced worthless—and he had Steve.

He still didn't react. Instead, he watched as the man grabbed another cage—he had too many cages; they worried Bucky, deeply, because why did he need so many cages?—and filled it with the remaining rats. They were all young, most of them big, some of them sizeable enough Bucky might have hesitated to take them on even in his alley days.

He didn't have space to worry about them because the man set the flute down and the mice discovered they were locked in a cage with a cat.

But Bucky didn't have space to worry about them, either, at least not right away, or about anything else, because Steve hit him like a small grey-furred bullet, burrowing into his chest. Bucky pressed his nose into his fur, purring hard, curving himself over Steve and curling his tail around him, and breathed in his mouse.

"That's not something you see every day," brought them back to now.

Bucky lifted his head and Steve turned, wrapping his tail around Bucky's front leg.

The ancient rat was watching them from his one eye, head tilted. "Are you going to eat him now, or save him for later?" He was standing not too far away, looking entirely unconcerned about his proximity to a cat. The mice, however, were as far away as they could get, flattened against the wire at the other end of the cage.

"I'm never going to eat him," Bucky said, disgruntled.

"Not like you mean, anyway," Steve added under his breath and he had to huff a tiny cat laugh. Even with the weight of everything, Steve was still Steve, still his mouse, the bravest of the brave, the boldest of the bold, and he rasped his tongue across his head.

The rat blinked his one eye. "Are you going to eat me?"

"You don't seem too worried about it."

"I'm old, generations of my children are running around the city, and my mate's long gone. I've already given my eye to one cat. What do I care if another one gets the rest of me?"

"If it's all the same to you, I'll pass."

"What about them?" He nodded at the mice, who stirred uneasily.

"No thanks."

"And what, we're just supposed to believe you?" a mouse called.

Steve's whiskers twitched. "He's not lying."

"He's a _cat_."

"He's still not lying. Look, I promise Bucky's not going to hurt you." Steve turned to look at him. "Give 'em your word."

It rankled. He was a _cat_, and Steve wanted him to promise a bunch of mice he wouldn’t hurt them? He wouldn’t, and these were far from usual circumstances, but that wasn't the _point_. The rat looked deeply amused by the whole thing and Bucky hunched his shoulders.

"Bucky?"

"Fine. I promise I won't hurt you," he muttered at the mice, tail lashing.

"Sure, we're just supposed to believe a cat—"

"Shut up," Bucky snapped, whirling to press his nose against the wire, because the man had crouched in front of the rat cage, was talking to them.

"I'm Brock," he said. "And you're all about to become my familiars."

The rats stared back at him from their cage. None of them moved. None of them reacted. Brock grinned and Bucky's previous dread tasted like ash in his mouth. He'd been right. _An army of familiars_. He could hear Natasha's voice, saying the words.

"You'll notice I'm not asking. In my experience, asking's a waste of time. If you ask, you run the risk of getting a no. Or if you're really unlucky, a nice scar." He leaned down and rolled up his pant leg, displaying four long white slashes across his calf. "Courtesy of my first attempt. I figured I'd ask a badger, makes sense given my name. This was her answer." He let his pant leg fall. "Next time I asked a cat. He just ignored me."

Bucky felt a burst of pride for his fellow feline that had seen this shit of a human for what he was and refused to have anything to do with him.

"Which was when I decided there had to be a better way."

The stillness of the rats was unnatural. Rodents weren't _still_. It wasn't in their nature. They were always moving, always sniffing, whiskers twitching, ready to doge or dart. It was the only way to survive when the whole world wanted to kill you.

The only time they were this still was..._ Oh. When they're being hunted. _

"The old witch who refused to teach me, she had a whole bunch of these…artefacts she called them." He rolled his eyes. "Anyway, she had this," he glided his fingers lovingly down the flute, "and she had one that keeps other witches out. Hides you from them." He smirked. "If she hadn't been so damn precious about not using magic to make money and just taught me, that one would have worked on me, but she didn't and they're all mine now. Just like you're going to be."

With a last grin at the rats, Brock let himself out of the pen and started working at a long table across from the double row of cages.

"A Piper." The old rat bared his teeth. "There's always another Piper."

"What?" Steve said.

"He said Piper." It was one of the mice, a female with a little splotch of white on her nose. She was creeping forward along with the other mice. Apparently they'd decided to take Bucky at his word. "That man, he's a Piper. That's how he got us. Right?" She looked up at the rat.

"That's right. I didn't know mice knew about things like Pipers."

She bristled. "We're not stupid. Just 'cause we don't go around making all these dumb formal rules for everything like you rats do doesn't mean we don't know about things."

"Uh, I'm a mouse and I've never heard of a Piper," Steve said.

The rat gave him a pitying look, but the mouse shot back, "You're human-born. And you're a, a _cat-lover_. You're barely a mouse at all," then cowered back as Bucky rose to his feet. No one talked to Steve like that. He wouldn't eat her, he didn't eat mice any more, and he'd promised, but that didn't mean he couldn’t show a little fang.

"Bucky." That was all Steve said, but he stopped, then sighed and lay down. "You're right," Steve told the mouse. "I am human-born. And I do love a cat. This one. And he's the best chance we have of getting out of here. All of us." He sat up on his back legs and groomed his whiskers. "Tell us about Pipers?"

"There's not much to tell," the rat said. "Pipers are death, but humans are stupid and humans don't learn and so the Pipers keep coming. First we die, and then the humans."

Bucky laid his ears back and Steve's ears canted outwards. Even the mice looked at each other.

"Could you tell us a little more than that?" Steve asked. "That's not helpful."

"What do you want to know?"

"Something _practical_?"

"Oh, well, in that case…" The rat curved his ragged ears towards Steve. "The Piper plays and every rat that hears follows. There's no choice. You can't fight it. Mice, too," he added, nodding at the mouse with the white-splotched nose. "But it's the rats they're really after. Then you die. Usually you drown, because the Piper leads you into water, but there's other ways of killing."

"But we're not dead," one of the mice pointed out. "And the rats, they're not dead."

"Yet," the rat said, and the mice shivered.

Bucky stared down at the cage below and said softly, tail lashing, "This isn't about killing." To Steve, he added, "Army of familiars."

Steve went still. "Didn't Natasha say that wasn't good?"

"Yes."

"She said familiars don't offer themselves to those kinds of witches." Steve's tail flicked back and forth. "But they won't have a _choice_, not if he's got that song on them. They'll walk right into the bond." He stretched up to press his paws against Bucky's nose. "Bucky."

"I can't, Steve. Whatever he's using, however he's doing it, Natasha's _gone_. Her magic's gone, I can't reach it, I can't use it. The runes on our backs may as well just be tattoos. I could scratch him up, do some serious damage before he took me out, but I can't open the cage. What am I supposed to do?" 

He could feel the answer like he sometimes felt his missing leg—he knew it didn't exist but it seemed so real he'd swear he could scratch with it. He could see the same answer shining out at him from Steve's gleaming black eyes.

"I'm your familiar."

"Steve."

"Only witches have familiars."

"I can't."

"Only witches can do magic."

"I'm a _cat_, Steve. Witches are _human_."

"Who says? Who says they have to be human? Who says they can't be a cat? Who says you can't be a familiar _and_ a witch? Who says you can't be _my_ witch? You're already my everything else."

The mice were staring at them, the curl of their whiskers and the tilt of their ears signalling utter confusion. The rat, ancient gnarled thing that it was, sat up on his haunches, like he'd finally heard something worth his interest.

Bucky's claws scraped on the metal floor. He could hear the rats in their cage, not desperate scrabbling but careful systematic gnawing, trying to escape. But just because it wasn't scrabbling, didn't mean it wasn't desperate. He could see the rows of cages along the wall. Perfect for holding more animals, bigger animals.

What if the flute worked on more than just rats and mice?

Below him, Brock stepped back into the pen and set a pot of glowing ink on the ground. It was open, a brush sticking out of it.

Then he put the flute to his mouth.

Bucky lost Steve. He lost the mice. He lost the rat. They pressed themselves against the wire, trying to follow a sound he couldn't hear, and he could do nothing to stop them. All he could do was watch as Brock lifted the rats out of the cage and painted the glowing symbol on their backs. The last time he'd seen that symbol was when Steve had become his familiar. 

_His_ familiar. Only witches had familiars.

He let his doubts fall away. It was simple, so let it be simple. If he had a familiar, he must be a witch.

And if he was a witch, he must have magic of his own.

Below him was an obscenity. A grotesque violation of everything the bond between witch and familiar was supposed to be. Brock was getting his familiars, but only because, spellbound by the song of the flute, the rats couldn't say no. 

In the cage, the mice, the rat, _Steve_, were clambering over him and hanging off the wire and scratching at the gate.

He closed his eyes. He knew how to call magic that wasn't his, and he'd felt Natasha call her own magic times beyond counting. All he had to do was put them together and believe the magic would answer him in his own right, that he had his own to call, that it meant something when it had tied Steve's heart to his…

The flood of power nearly knocked him unconscious. With no familiar to help control it, it slammed into him, raw and burning, and flattened him to the cage floor. _Is this what it was like for Natasha before she found me? _He pulled back, let most of it go until it was just a trickle, but it was there. It was _his_, no hint of Natasha's pine and cloves. Instead the air smelled of fresh turned earth and sunshine.

_My magic smells like dirt and the sun. _My magic. _My_ magic.

He tried, but It wasn't strong enough to break through the song.

Brock _must_ have felt the explosion of magic, but he didn't react, didn't pause. When he finally let the flute fall, the rats crouched at his feet like obedient dogs. _What had he done to them?_

Steve shook his head, ears twitching, then he was there, his golden true-self standing between Bucky and the magic. Steve, his familiar. "More. Pull more. Pull as much as you need to, Bucky. I've got this."

The cage creaked as the wire buckled inwards. The mice hunkered down, piling together. Brock was staring up at them, trying to…crush them? Crush them. Bucky yowled and _pulled_, magic flowing thick and fast, and pushed back.

There was no finesse in what Brock was doing, no subtlety, just brute force, but brute force would kill them all if Bucky couldn't stop it. Then Brock would be loose in the city with his army of familiars and Natasha would be facing him down with no familiar of her own.

That wasn't going to happen and Steve wasn't going to die in this cage, even if Bucky had to burn himself to ash from the inside out to stop it.

He shifted his back paws, planted his front, and opened himself up to everything the magic would give him. It roared down on him like the car that had hit him, but this time he'd invited it. This time, it was his choice.

Steve fought to control it, to keep it from burning him out, but he was faltering. He shoved his front paws against Bucky's leg and bore down, sparks dancing from his whiskers to Bucky's fur.

The mouse with the white splotched nose sat up on her back legs, nose twitching, then bounded forward to press her paws to Steve's side. "I don't know what you're doing, but if I can help, I'll help."

Suddenly they were three, Steve reaching out to her to balance the flow of power, just like he'd once done for Bucky and Natasha. She shook her head, twitching and jumping, but her front paws never left Steve's side. Then they were four as another mouse joined, then five and six and then Bucky stopped counting because there were a sea of mice surrounding Steve, the magic bouncing between them, growing bigger and stronger and fiercer with every leap. Steve poured it into him and it coursed through him as gently as a loving touch. He turned, almost floating in a bubble of predatory peace, sliced a metaphorical claw through the barbed wire tether binding the rats to Brock, then blew the door off the cage.

Brock hit his knees as the magic backlashed, and Bucky leapt from the cage, casting the spell to change Steve to human as he sank his claws and teeth into Brock's face. Brock screamed, but it was drowned out by Steve's roar. Brock ripped Bucky off his face and hurled him away, but Steve caught him in one hand, dropped him gently to the floor, and slammed into Brock.

There was a lot of him to do the slamming.

With the rune dead, Bucky's magic had shaped a new body for Steve. Shaped it from the fierceness of a dozen angry mice, from Steve and Bucky's combined fury and, most importantly, shaped it from Bucky's heart. From Bucky's love, yes, but also from Bucky's truth: that Steve's bold and brave self was larger than any body could contain.

This one, however, would come close.

Steve loomed large over Brock, wide and tall and with more muscles than Bucky had ever seen on a human in real life. It took him very little effort to knock Brock unconscious. Bucky knew it took more effort to stop there, to leave him unconscious and bloody on the grimy cement floor and not finish the job. He knew, because his instincts were screaming _kill him_. Steve's would be doing the same. However much a cat's—or a mouse's—enemies weren't properly dealt with until they were dead, they were more than just a cat or a mouse. Much as it pained him, they couldn't kill him. He rubbed his head against Steve's leg, and from Steve's sigh he knew Steve understood.

"You're not going to kill him?" the ancient rat asked.

Bucky looked up. The rat and the mice were gathered at the front of the cage, looking down. The other rats, the ones Bucky had freed, were hunched at the bottom of one of the metal panels.

"No."

"That's a damn shame. Get that giant mouse to get us out of here, will you?"

"What did you do?" the white-splotched mouse asked Bucky. "What did _we_ do?"

"Magic," Bucky replied, placing his paw on Steve's foot. "You did magic and you helped set the rats free and kept a seriously bad human from doing who knows what."

"All humans are bad," she said dismissively, "but I'm glad we saved the rats." She curved her ears towards the ancient rat standing next to her. "Does this mean you owe us? Don't you rats have rules about things like that?"

"I thought you didn't like all our _dumb formal rules_."

"We like 'em fine when they can get us something," one of the other mice said, and she twitched her whiskers in agreement.

"Oh, in that case." The rat sighed. "Yes, we owe you something."

While the rodents chattered, Steve crouched down and curled one of his large hands around Bucky's head. Bucky purred as he pushed his cheek into Steve's touch. He _liked_ the new hands. They had all sorts of potential. "I wish I knew what they were saying."

"I'll tell you later," Bucky promised, even though he knew Steve couldn’t understand him, either, and pointed his nose at the cage.

"That I can figure out just fine." He cupped his hands together and held them at the front of the cage.

There were a lot of dubious whisker twitches. Most of the mice retreated. The mouse with the white-splotched nose held her ground, sniffing madly, then said, "I take back what I said before. Human-born or not, even with whatever this is," she waved a paw at his human body, "you've got the heart of a mouse," and stepped onto his hands.

The rat followed, and then the rest of the mice, and Steve lowered them to the floor—then pulled down the metal panels, leaving the way clear for them to leave, and brought his foot down on the wooden flute, crushing it beyond repair.

The rats surrounded the ancient rat, eyeing Bucky and Steve suspiciously, but he waved a claw. "The mice are coming with us." With no more than an exchange of ear flicks, they opened their ranks and left room for the mice. "Come on," the ancient rat said, and they skittered in, the white-splotched female making her way to stand beside him.

Faster than Bucky would have thought possible, they scampered away and disappeared into the shadows.

Steve scratched his head. "Did they even say goodbye?"

"No," Bucky replied, disgruntled and a little offended, adding a _mrow _for good measure. "I guess those formal rules about owing something don't extend to us."

Steve pushed one of the metal panels over and sat on it, Bucky climbed onto his lap, and then Steve wrapped his arms around him, and Bucky cuddled as close as he could get, Steve's fingers sinking into his fur. 

"I guess," Steve said after a while, "we'd better call Natasha."

Bucky gave an agreeable huff and while Steve dug in Brock's pockets for a phone, he once more reached for the magic. Something was blocking him from Natasha. From what Brock had said it was a thing, so if he could just find it…. _There. _On top of the long table he found a wooden ball, intricately carved, with another ball inside it, just as intricately carved, and another inside that and so on and so on. It was the source of magic that was blocking him.

He considered it, then put a magical, metaphorical claw in and ripped the spell right out of it. It was surprisingly easy, but then cats did have a gift for destruction, and suddenly Natasha was back.

She was there, waiting for him, her magic there to call on, and he twisted, uncomfortable, fur puffing out, while his magic and her magic circled each other, spitting and territorial. But in the end magic was magic, and eventually they settled, purring together like a litter of kittens, but he'd missed most of Steve's phone call while they'd sorted things out.

"He's fine, Natasha. I promise." Steve's eyes were wide, and Bucky could hear the fury radiating from the phone along with the sound of Natasha's voice. "I know, I know you couldn't, but I promise, he's okay. We dealt with it. The guy's still alive, because we figured you'd want that." It was obvious from Steve's voice, and the way he nudged Brock's still unconscious form with his toe, that it hadn't been his first preference. 

Natasha's voice dropped in both volume and anger.

"I have no idea where we are. It's a dirty basement. Lots of cement. Can you find us?" A pause. "We'll stay put. I swear to you that Bucky's fine. I would never lie to you about that." There was a longer pause, then Steve said softly, "Natasha. I promise I'm okay, too."

He hung up the phone, dropped it on Brock's back, and scooped Bucky into his arms, burying his face in the fur on his back. "Your witch is scary."

Bucky started purring, squirming around so he could put his paw on Steve's face. "You have no idea."

Steve kissed his stomach and they sat together until the door banged open and Natasha's magic filled the room, the scent of cloves and pine not quite masking her anger and fear. She leapt down the stairs, hauled Steve to his feet, and wrapped her arms around them both.

Bucky shoved his head under her chin, purring to rattle all their bones, while Steve just stood awkwardly in her embrace, the arm not cradling Bucky dangling at his side, and said, "I'm not wearing pants."

Natasha squeezed him harder. "Just this once, it doesn't matter," she said fiercely, and Steve folded his arm around her.

"But I've got 'em for you," Sam called as Redwing flew down to perch on the cage. "You know, because it's gonna matter in a minute." He stopped at the bottom of the stairs. "But I'm not sure they'll fit you," he added. "Since you're apparently a giant now?"

* * *

What came after was easy. Things often were once Natasha decided to deal with them. Although, from the way she'd stared down at Brock while Steve explained what had happened and put the shattered remnants of the wooden flute in her hands, Bucky knew she'd had the same _I can't kill him_ thoughts as him and Steve_. _There were times Natasha could be decidedly cat-like in her approach to problem solving.

Neither he nor Steve knew what had become of Brock. Natasha had called Clint, and Clint and Sam had taken him…somewhere, but where it was, what was being done with him, was a mystery. Natasha was satisfied, though, and that was good enough for Bucky.

After, when they were home, when everything was over, he and Steve had ended up sleeping in Natasha's room, Steve curled on Bucky's back, Bucky curled at the bottom of her bed. They hadn't started out that way, but after the third time she'd woken up to check on them Bucky had sauntered down the hall with Steve perched between his shoulders and hopped up to start kneading the quilt.

Her little smile had been both thanks and wry acknowledgement that she was being ridiculous. His brief purr had answered both: she was his witch, he was her familiar, and for however short a time they'd lost that.

That had been last night.

Tonight, she was fast asleep in her room at the end of the hall with the door firmly closed. Which was good, since Bucky was stretched out on their couch with Steve lying across him.

Steve was bigger than him. Taller, broader, probably stronger. Bucky could use him as a blanket if he wanted to—and he intended to at some point, just not now. Now, he pressed his hand against Steve's cheek. "You're a giant."

The corner of Steve's mouth twitched.

"I wasn't sure you would be when you changed again, if maybe it was a one-off thing."

"Really?"

He shrugged and pressed up to nuzzle Steve's cheek before letting himself fall back to the couch. "Natasha said I made your first shape, the small one, when I cast the spell the first time. That it was partly formed by the way I saw you, that it was anchored to the rune on your back."

"And?"

His eyes narrowed. Stupid stubborn mouse was going to make him say it. "And when you couldn't use the rune and I had to cast it again, I had to make a new shape with my magic. And you came out like this."

Steve grinned, entirely smug, and kissed him. "You think I'm a giant."

"A giant pain in my ass, maybe."

Steve laughed and propped himself on an elbow so he could run his fingers through Bucky's hair. "This is the shape you gave me when we were fighting together. This is the shape you gave me when you needed me to help protect humans we don't even know." He kissed him again and lifted his head just enough to add, "And _rats_, you wanted to save _rats_, or do you think I didn't know that what he did to them was part of what made you so angry?"

Bucky raised one deeply dubious eyebrow. "Did you forget that I'm a cat?" He didn't deny it, though, because lying to Steve wasn't something he'd ever do.

"I didn't forget that you're Bucky." It was soft and low and sweet, more sung then said, and Steve brushed his lips against his cheek.

That was flat out cheating. He narrowed his eyes, but Steve's just gleamed back at him, as bright in brilliant blue as they were when they were black.

"Bucky. This is the shape you gave me when you accepted you were a witch. What would ever make you think I'd choose something different?"

He didn't have an answer. Put like that, he sounded stupid to have ever questioned it.

Steve smiled slow, and kissed him slow, dragging his mouth away before Bucky could deepen it. Ignoring Bucky's disgruntled huff, he pressed his nose against Bucky's. "And if you'd been thinking, you'd have known it's what you wanted, too, because I can't change without the rune. Not on my own."

Bucky tried to flatten ears he didn't have.

Steve tried, and failed, to hide his laughter by pressing his face into Bucky's neck. "You wrote over the old shape when you cast the spell."

Embarrassed, he rubbed his cheek against Steve's. "Is it too late to say I meant to do that?"

"You're a cat," Steve said. "It's never too late to say it." He lifted his head, laughter in his eyes. "But that doesn't mean I'll believe you." 

"You're my familiar; is it asking that much for you to _pretend_ to believe me?"

"Bucky." Steve kissed him and Bucky wrapped his arm around Steve's neck. "You're my witch." Steve kissed him again, leaning into it, and Bucky curled a leg over Steve's, getting as close as he could as the kiss went on and on. Steve's eyes gleamed with mischief as he pulled back and Bucky curled his fingers in Steve's hair. "You're my everything." He kissed the tip of Bucky's nose. "But that's never gonna happen." 


End file.
